ABINITIO STRUCTURAL AND THERMOELASTIC PROPERTIES OF ORTHORHOMBIC MGSIO3 PEROVSKITE

被引：39

作者：

WOLF, GH

BUKOWINSKI, MST

机构：

[1] Univ of California, Berkeley, CA,, USA, Univ of California, Berkeley, CA, USA

来源：

GEOPHYSICAL RESEARCH LETTERS | 1985年 / 12卷 / 12期

关键词：

CRYSTALS - Structural Analysis - GEOLOGY - THERMOELASTICITY;

D O I：

10.1029/GL012i012p00809

中图分类号：

P [天文学、地球科学];

学科分类号：

07 ;

摘要：

We present results of an ab initio study of the structural and thermoelastic properties of orthorhombic (Pbnm) MgSiO//3 perovskite as a function of temperature and pressure. Self-consistent free energies are computed using quasiharmonic lattice dynamics with interatomic potentials derived from an electron-gas formulation. At zero pressure the calculated bulk modulus and thermal expansion are in excellent agreement with the available data. We find that for high-temperature isotherms, a finite-strain decompression of the high-pressure equation of state of perovskite substantially overestimates its zero-pressure density and bulk modulus; hence, constraints on the chemical composition of the lower mantle, based on a comparison of the decompressed seismological properties with zero-pressure laboratory data may significantly overestimate the proportion of perovskite in the lower mantle.

引用

页码：809 / 812

页数：4

共 15 条

[1] FINITE STRAIN ISOTHERM AND VELOCITIES FOR SINGLE-CRYSTAL AND POLYCRYSTALLINE NACL AT HIGH-PRESSURES AND 300-DEGREE-K [J].